Since our last newsletter published May 2017, the collection of the Virtual Museum of the History of Mineralogy has continued to grow and the 5 items below were added recently. We would like to stress that these additions all came from enthousiast collectors willing to share their interest in early mineralogy and crystallography.
- A vertical circle goniometer of the Wollaston type signed by Jules Duboscq. This goniometer was made before 1883 and therefore earlier than the same type of goniometer also present in the collection of the VMHM signed by the Parisian constructors J. Duboscq and Ph. Pellin whose merging of firms dates back to 1883
- A projector polariscope for the demonstration of polarization phenomena in crystals by means of projection. This interesting and beautiful instrument is signed by J. Duboscq and Ph. Pellin and may therefore be dated end of the 19th century.
- An inclinable Biot-type reflecting polariscope was produced by Lerebours in Paris during the first half of the 19th century with the same purpose to demonstrate and investigate polarization phenomena in crystals. It comes with accessories and mutually interchangeable parts ; interestingly, two inclinable mirrors are present : one is plane black glass while the two faces of the second have a black glass mirror and a stack of plate glass.
In this category two new instruments were proposed by a Belgian collector who previously contributed and enriched this spectroscopical section
Your interest in the Virtual Museum of the History of Mineralogy is stimulating for us and the contribution by some of you by pictures and information to be added in the collection will always be greatly appreciated.
Claude Hootelé, Paul Tambuyser